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Which mineral is a natural magnet?

Magnetite is a mineral, iron oxide (Fe2+ and Fe3+), spinel group.
Magnetite forms a solid solution with jacobsite (jacobsite) Mn2+Fe3+2O4 and magnesioferrite (magnesioferrite) MgFe3+2O4.

Other names (synonyms):

  • iron magnetic ore,
  • Ziegelstein,
  • magnetic iron ore.

Varieties:

  • Mushketovit,
  • Titanomagnetite,
  • Chrome magnetite,
  • Ishkulit.

Chemical composition

FeO— 31; Fe2О3 – 69; impurities of titanium, chromium, magnesium, manganese, nickel, vanadium, and aluminum are common.

Magnetite is one of the most common oxide minerals and is found in a wide variety of geological formations.

The magnetite mineral can be igneous (in rhyolites, granites, trachytes, syenites, andesites, diorites, gabbros, basalts, pyroxenites, peridotites, olivinites, pegmatites), hydrothermal and metamorphic – in skarns; in metasomatites – (pyroxene-amphibolo-magnetite, apatite-phlogopite-magnetite, magnetite-phlogopite-calcite, magnetite-calcite groups); in talc-chlorite, talc-magnetite shales and serpentinites; in regional-metamorphic. g.p., in placers, rarely sedimentary.
Magnetite is the main component of oxide iron ores – ferruginous quartzites, magnetite skarn and carbonatite ores, as well as magnetite “black sea sands”.

Main diagnostic signs

The mineral magnetite has strong magnetic properties and is attracted by a magnet.

Behavior in acids: difficult to dissolve in HCl. The powder dissolves noticeably.

Place of Birth

Large industrial deposits of the mineral magnetite in Russia are located in the Kursk Magnetic Anomaly, in the Murmansk region (Kovdor deposits), in the Urals (Magnitogorsk).
Deposits of ferruginous quartzite are known in Ukraine (Krivoy Rog), magnetite is mined from skarns in Azerbaijan (Dashkesan deposit). Also, deposits of the mineral magnetite are known in Italy, Sweden, Greenland, Brazil, the USA, South Africa, Canada, etc.

Application

The mineral magnetite is the main ore for iron.

This stone is not used very often in the jewelry industry. Usually it is used to make beads, bracelets, and rosaries. Magnetite is suitable for making both women’s and men’s jewelry. In the chemical industry, this rock is used to obtain vanadium and phosphorus.

Today magnetite is also widely used. This stone is especially popular in China.

History of the stone

The first mentions of magnetite are found in Ancient Greece. The stone was in great demand during the Middle Ages.

Several decades ago, in Asian and European countries, this breed was used to determine the direction of movement, i.e. the stone acted as a compass.

Evidence has been found that this mineral was used by the ancient Olmecs, tribes that lived in Central America. They made figurines from stone that acted as various symbols. Many peoples used magnetite to make mirrors.

Properties of the Mineral

Color iron-black, sometimes with blue tarnish
Line color the black
Origin of the name According to Pliny the Elder, from the Greek. Magnes – named after the legendary shepherd who first found a natural magnetic stone that attracts iron in the city of Ida (Greece). Or in the area of ​​Magnesia in Macedonia
IMA status valid, first described before 1959 (before IMA)
Chemical formula FeFe 2 O 4
Brilliance metal
mat
semi-metallic
Transparency opaque
Cleavage not visible
Kink conchoidal
uneven
Hardness 5,5
6
Thermal properties P. tr. doesn’t melt. In an oxidizing flame, it first turns into maghemite, then into hematite, losing its magnetic properties
Typical impurities Mg,Zn,Mn,Ni,Cr,Ti,V,Al
Strunz (8th edition) 4/B.02-20
Hey’s CIM Ref. 7.20.2
Dana (8th edition) 7.2.2.3
Molecular weight 231.54
Cell Options a = 8.397Å
Number of formula units (Z) 8
Unit cell volume V 592.07 ų
Twinning Common by , with the same face as the composition face. Twins flattened parallel to (common spinel law twins), or as lamellar twins, producing striae on . Twin gliding, with K1, K2.
Point group m3m (4/m 3 2/m) – Hexoctahedral
Space group Fd3m (F41/d 3 2/m)
separateness by distinct, also reported separately by , , .
Density (calculated) 5.2
Density (measured) 5.175
Internal reflexes no
Refractive indices n = 2.42
Maximum birefringence δ = 0.000 – isotropic, does not have birefringence
Type isotropic
Optical relief very tall
Color in reflected light gray with a brownish tint
Selection form crystals of octahedral, less often rhombic dodecahedral habit with simple forms (100), (111), (110), (211>, (210) and characteristic diagonal shading on the faces (110), crystalline intergrowths and aggregates, druses, brushes, dense granular and continuous masses, dissemination in igneous rocks, individual grains in placers. Spherulites, kidney-shaped aggregates, oolites, pseudomorphs of magnetite after hematite (musketovite), chrysotile-asbestos, perovskite and other minerals are also known.
Classes on taxonomy of the USSR Oxides
IMA classes Oxides
Syngonia cubic
Microhardness VHN100=681 – 792 kg/mm2
Magneticity Yes
Literature Mazurov M.P., Grishina S.N., Titov A.T. Magnetites from magnesian skarns at the contacts of dolerites with rock salt // Geology and Geophysics. 2004. T. 45. No. 10. P. 1198-1207.
Stebnovskaya Yu.M. Magnetites of iron ore deposits. . Kyiv Sciences. Dumka, 1985. – 103 p.
Chernysheva L.V., Smelyanskaya G.A., Zaitseva G.M. Typomorphism of magnetite and its use in prospecting and evaluation of ore deposits. M., 1981

View the mineral Magnetite in mineral stores

Photo of Mineral

Related Articles

  • Magnetite, also known as magnetic iron ore

Magnetite crystals are attracted by a magnet like soft iron, strong masses themselves act like a magnet

Magnets were known to mankind even before the advent of our era. The Greeks found natural magnets in the mountainous region of Magnesia (Mounts Sipylus and Magnessa), the inhabitants of this area were called magnets.
In ancient times magnet called differently: “guard stone”, “Hercules stone”, “blood-forming stone”, etc. And each of the names reflects one of the many amazing properties of this natural mineral, more precisely, iron oxide.
Medicinal and magical properties: its magnetic properties have been known since ancient times in China. There it was considered a feminine (YIN) stone, since it attracted iron to itself just as women’s charms attract the hearts of men. It was also considered a strong protective stone, protecting against enemies.
Ancient manuscripts mention the magnetic gates of one of the princely castles, through which no armed person could pass. And one of the legends tells how magnetite helped the Chinese emperor Huang Ti win a brilliant victory over his enemies in 1110 BC. The victory was achieved by outflanking the enemy troops from the rear, and the maneuver was carried out in thick fog. Special chariots made of magnetite helped him stay on track. This is how magnets found their practical application.
And in the Middle Ages, natural magnets were carved from the “Hercules stone”, which could lift large weights, several times greater in weight than themselves. magnets. The famous physicist Newton possessed a miraculous ring made of magnetite, which could lift iron objects with a mass 50 times greater than its own. His “magic” ring, in which, instead of a precious stone, a natural magnet of extraordinary strength was set in gold. It is not surprising even for a scientist: many legends and traditions are associated with the magnet. It was believed that a magnet could open locks and extract gold from underground. They said that somewhere in the sea-ocean there are magnetic rocks that pull out nails from ships passing by. They tried to build a perpetual motion machine using magnets.

Magnetite in natural conditions looks different: usually in the form of continuous granular masses in iron ore deposits and relatively rarely in the form of clear octahedral crystals (octahedrons). The crystalline magnetite of the Kovdor iron ore deposit on the Kola Peninsula enjoys well-deserved fame among collectors and stone lovers.
During a thunderstorm, lightning strikes most often occur in places where magnetite deposits are located (in Russia these are: the Kola Peninsula, Kursk Magnetic Anomaly, Magnitnaya Mountain in the Urals).

The Chinese called natural magnets, which were black pebbles, “chu-shi,” which translated means “loving stone.” By the way, in French the magnet is called “eman” – “loving”. This is probably connected with the thought: reaching out means loving.
Master restorers can already tell you exactly what ancient compasses looked like, compasses that would be 3000 years old today. The pages of ancient chronicles are full of descriptions of battles, which warlike emperors won thanks to “magic chariots” – a kind of modification of the compass. In the same chronicles there are descriptions of magnetic gates through which an ill-wisher with a weapon could not pass, magnetic pavements and other uses of the “chu-shi” magnetic stone, simply a magnet.

Chinese folklorist Su Matzen collected a library of ancient chronicles many years ago. Here is information from them related to magnets.
Emperor Huang Ti, who lived 2 years before Su Matzen, attacked the enemy from the rear in thick fog and defeated him. Huang Ti was helped to navigate in the fog by figures mounted on carts with an outstretched arm, always pointing to the south.
Emperor Cheu Kun decided to thank the ambassadors of distant Yue-Chan (Vietnam) for the signs of attention and friendship, expressed in the form of offering him white pheasants, and presented them with five road chariots, arranged so that the carved man always pointed to the south. Yue-Chan’s ambassadors set off on these chariots, reached the seashore, passed the cities of Fh-Nam and Lin-N, and a year later arrived in their homeland.
Perhaps these legends, dating back to 1110 BC, contain the first mention of a compass, that is, a usefully used magnet.
Apparently, in the future the secret of making magnetic chariots with a south indicator was lost, since in the 5th century “Emperor Tai Wu Di of the Wei Dynasty ordered Kuo Cheng Ming to build this kind of chariot. He worked for a whole year, but without success. Then the emperor entrusted this task to Ma Yo, who actually managed to build it. For this, Kuo Cheng Ming poisoned him with the poison of the feathers of the Chin bird. Ma Yo’s design was considered excellent.”
It is unknown whether Ma Yo’s design was identical to earlier designs.

But even if, for reasons of scientific rigor, it is impossible to count the ancient legend among the first mentions of a magnetic compass (you never know on what principle, perhaps unknown to this day, these south indicators worked!), the inhabitants of the Ancient East still need pay tribute to the first useful use of a magnet. Thus, in the encyclopedia of 121, Hun Chin describes for the first time both a magnet and a magnetic needle. The chronicle of the XNUMXth century directly states that “foretellers rub the end of a needle with a magnetic stone to give it the property of pointing to the south.”
These circumstances could not prevent the Italians from building a monument in Naples to a resident of the city of Amalfi, Flavio Gioia, who, in their opinion, invented the magnetic compass in 1302. The fact that Gioia was not the first is evidenced by the mention of the compass of a monk of the Order of St. Alban in 1187, the poems of the poet Guyot of Provence, written in 1206, and the reflections of Pierre Peregrine, dating back to 1269.
However, the beautiful legend about Flavio Gioia, the inventor of the compass, still lives among the Italians.
. A long time ago, when the city of Amalfi stood, like Venice, on the sea, Flavio Gioia, a goldsmith and inlay maker, lived there. He was poor and cheerful, and besides, he loved the black-eyed beauty Angela, the daughter of the rich fisherman Domenico.
The fisherman Domenico did not want his daughter to marry the “land-dwelling” Joya, and set a difficult condition for Flavio – to learn to swim in a straight line in the fog and in the night. It is clear that this condition cannot be met. But Flavio was not one to lose heart. In his work, he used a magnetic stone to inlay small pieces of iron. Once Flavio noticed that if you put this stone on a piece of cork floating in water, it always turns in one direction. So, according to legend, Flavio invented the compass. A month later he married the beautiful Angela.
Flavio received Angela, the fishermen received a compass.
If we approach the poetic episode from a historical perspective, perhaps we should assume that although Gioia did not invent the compass, it was apparently he who gave the compass its modern appearance, providing it with a disk with divisions – a card.

The scientist-monk Alexander Nekam in his works “On the Nature of Things” and “Auxiliary Means” indicated that the magnetic compass needle is mounted on a pin, and does not float in a special vessel with water, as follows from earlier works. The Italians call Flavio Gioia the inventor of the compass, the Germans are sure that the compass was invented by the Cimbri and the Teutones, because most nations call the thirty-two points of the compass in Germanic.
The Vikings, the British, and the Chinese consider themselves to be the first inventors of the compass.
Apparently, the most accurate conclusion may be the following: the magnetic compass was invented in different parts of the world by different people, whose names are hidden from us by the veil of time.
It is obvious that magnets “worked” during the era of the Great Geographical Discoveries: Henry the Navigator discovered the western coast of Africa, Bartolomeu Dias – the Cape of Good Hope, Christopher Columbus – America, and Ferdinand Magellan circumnavigated the world. And MAGNETS helped them!
With the development of progress, artificial magnets appeared – these are magnets based on ferromagnetic substances. These magnets are capable of holding more than 5000 times their mass.
For comparison, a natural magnet stored at the University of the Estonian city of Tartu lifts a load of 40 kg with its own weight of 13 kg.

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